A rotogravure printing press uses a direct printing process where the ink is transferred directly to a printing surface (e.g. a paper or plastic web) from small cells that are engraved into the surface of a gravure cylinder. The rotogravure printing press typically consists of the gravure cylinder, a doctor blade, an impression roller, an ink pan system, and an inking system. In operation, the gravure cylinder is rotated in the filled ink pan system and the engraved cells pickup the ink as the gravure cylinder turns. Excess ink is wiped from the gravure cylinder surface by the doctor blade and is returned to the ink pan system. The printing surface (e.g. the paper or plastic web) is pressed onto the gravure cylinder surface by the impression roller, resulting in a direct ink transfer from the inked cells of the gravure cylinder to the printing surface.
The ink pan system consists of two pans, an inner pan and an outer pan. Each pan may have a concave shape. The inner pan holds the ink for pickup by the rotating gravure cylinder. The outer pan receives ink from the inner pan via gravity. In operation, the ink is pumped into the inner pan and then drains through small holes in the bottom of the inner pan and/or cascades over the inner pan into the outer pan. The ink drains out of the bottom of the outer pan through an opening into a drain hose and then into an ink sump via gravity.
There are several problems with the foregoing two pan system. Some known problems include: the amount of ink needed to operate the rotogravure press, the amount of ink left in the ink pan system after operation, the pump pressure needed to sustain the amount of ink in the ink pan system, the amount of man hours needed to clean parts after operation, and the scumming, bubbling, and swirling affect of the ink in front of the gravure cylinder which causes color voids in the print.
There is a need for an ink pan system that addresses the foregoing problems.